The invention relates to the stringing of racket frames and particularly to an apparatus for lacing the lateral strings in such a frame after the frame has already been strung with the longitudinal strings thereof. In the process of stringing rackets such as tennis rackets or squash rackets, it is the usual practice to clamp the racket frame onto a support which is rotatable on a verticle shaft and to first string the frame with the longitudinal strings (forming parts of a single length of string) which strings are properly tensioned and secured. Next the lateral strings are applied which likewise form parts of a single continuous length of string. For lacing a lateral string, the string is inserted through a string hole of the frame and is passed alternately under one longitudinal string and over the adjacent longitudinal string in the manner of a flat weave, whereupon the string is passed through the opposite string hole of the frame and is properly tensioned and temporarily secured by a string clamp until the next lateral string has been laced in, tensioned and secured. Lacing the lateral strings by hand is a time consuming operation which demands considerable manual dexterity. In pulling the string through, these rub along the several longitudinal strings which causes wear and, in the case of catgut strings, leads to fraying, particularly if on lacing the first of the lateral strings, a great length of string has to be drawn through the frame.
To facilitate the lacing of the lateral strings, it is known to use an apparatus comprising a lower first beam having in its upper surface, a row of vertical slots spaced at a distance corresponding to twice the average pitch distance between the longitudinal strings of the racket frame to be stringed, the upper surface of said first beam forming a plurality of upper string support surfaces between these slots. Said first beam further contains a longitudinal slot in which an upper gripper second beam is vertically slidably mounted, an operating mechanism being provided for moving the gripper second beam between a raised and a lowered position with respect to the lower first beam. The gripper second beam is provided with upwardly extending wire hooks which, in the upper or open position of the gripper second beam and with the apparatus placed crosswise against the underside of the longitudinal strings, can be hooked over alternate longitudinal strings whereby on closing the apparatus by moving the gripper means beam downward with respect to the lower first beam these strings are pulled into the slots of the lower first beam; whereas, the remaining longitudinal strings find support on the support surfaces of the lower first beam. In this way, a channel is formed through the longitudinal strings through which a lateral string can be easily passed. This known apparatus, however, has the disadvantage that after lacing-in a lateral string and again opening the apparatus, the hooks thereof must be removed from the longitudinal strings which they engage and must be placed over the adjacent longitudinal strings in order that the location of the channel through the longitudinal strings can be changed when the apparatus is again closed to obtain the required flat weave when introducing the next lateral string. This known apparatus has the further disadvantage that when pulling through the lateral strings, the latter still chafe along the longitudinal strings supported on the support surfaces of the lower first beam.